Printing inks of the type generally used for commercial printing of graphic materials such as brochures, flyers, posters and other, similar materials, generally are substantially viscous and sticky, having consistencies ranging from extremely thick and gelatinous to a pourable, syrupy consistency. In the past, it has been common to package such printing inks in standard sized metal cans. These cans typically are cylindrical sheet metal cans having a shallow slip-on lid that is adapted to be pried off and replaced over the cans for resealing the cans, similar to conventional paint cans. The inks generally are sold in standard sized containers of between one to ten pound increments, with five pound increments generally being a preferred standard size.
In use, an operator or worker removes the lid using his hands and, if necessary, a prying tool and then scoops or spoons out the ink from the container using a spreading tool akin to a large spoon or spatula. The ink is generally scooped onto and spread about a mixing or weighing table, or can be applied to a supply well for a printing press or directly onto the press itself. After a desired portion of ink has been extracted from the container, the metal top is replaced over the container and tapped down to reseal the container.
A principal problem with such cans traditionally has been that they are extremely awkward to handle and use. This makes the process of extracting the ink from the cans difficult and somewhat messy as the worker tries to hold the bulky five to ten pound can in one hand, or under one arm, while trying to spoon out the thick, gelatinous, sticky ink using the spreading tool with their other hand. Such a method does not enable much control as to how much and how the ink is deposited on the mixing/weighing table or press and is extremely messy, with the ink oftentimes covering not only the spreading tool but the sides of the table, the can, and the worker. As a result, extensive and time consuming cleanup of the work area and the spreading tool(s) is required.
In addition, when the lid is replaced on the can, it tends to trap air within the cans between the lid and the ink within the can. Because of the construction of the can, this air generally cannot be evacuated prior to the resealing of the can with its shallow metal lid. This air, when it comes into contact with the ink within the can, causes "skinning" of the ink wherein a relatively thick crust or layer of dried ink, a "skin", forms on the top of the ink. Such a crust or skin first must be removed and discarded before additional ink can be removed from the can. This process must be repeated each time the can is opened and ink extracted therefrom until the can is empty. This creates a significant amount of waste of ink, upwards of 10% of the ink in the can, due to the continual skinning of the ink within the can. Also, if the can is not completely sealed, the ink can become dried out and thus wasted.
Further, EPA regulations classify printing inks as a toxic substances, and thus require that substantially all of the ink be removed from ink cans, with less than 1% of the volume of ink being left within the can in order for the cans to be discarded. Thus, the cans must be completely and carefully scraped and cleaned of ink prior to disposal of the can. Again, this is a messy, time consuming and somewhat difficult job that also increases the clean-up time and costs of using the cans. The cans'bulk further creates increased expense in shipping and storing, as even empty cans take up a significant amount of space, which space cannot be recaptured until all of the ink is completely exhausted from the cans and the cans are discarded.
Recently, attempts have been made to package printing inks in smaller size amounts in paper and/or plastic "caulking tubes" from which the ink can be dispensed using a caulking gun. Such tube containers appear to be sufficient for delivering or dispensing some printing inks in approximately one pound increments. However, for increments above one pound and for more viscous inks, these caulking tube type containers are not practical. Given the high viscosity of printing inks, as greater than one pound increments are used in the tubes, the pressure created within the tubes as the ink is attempted to be forced out of the ends of the tubes, generally tends to split the seams connecting the spout and lid to the tube body, in addition to splitting the tube itself causing leakage, etc. To prevent such splitting, it generally is necessary to use thicker, heavier gauge plastics and paper or other stronger, more expensive materials for tubes containing greater than one pound increments of printing and other types of inks, leading to greater expense. In addition, stronger, heavier gauge caulking guns or applicator tools also generally are required to enable sufficient force to be exerted on the sliding bottoms of the caulking tubes to force the ink out of the tubes. This further increases the expense of using such caulking tube type delivery systems by requiring special applicators or guns.
Accordingly, it can be seen that a need exists for a container for the storage, transport and dispensing of printing inks that is easy and economical to use and which can be used for storing and dispensing varying amounts of printing inks without requiring special tools and without creating a mess or requiring extensive clean up, while substantially reducing the incidence of waste of the printing inks due to skinning.